Transmission mechanisms are used for applications in automation and robotics. In this context, apart from a low mass of the transmission mechanisms, the speed and force of the force transmission are also important. High precision of the output of such transmission mechanisms is particularly important for positioning purposes. In this context, the design and development of lightweight movement mechanisms is often motivated by the structural design of movement mechanisms related to biological applications.
DE 689 21 623 T2 discloses an adjustment element with an inflatable chamber and a tensile fiber. This is not driven by a traction rope, however, but by inflating and/or emptying a component of the chamber. For this purpose, the fiber extends along a wall of the chamber component and is embedded therein, while a further wall of the chamber component is essentially inextensible. During the elongation of the chamber component, the combined length of the chamber component and the connecting link is reduced.
DE 197 19 931 A1 describes a device for compensating vibrations in a swiveling arm of a robot, where any vibrations that occur are attenuated by means of tension springs, a measuring device, and by generating controlled antagonistic forces of the semi-rotary actuator.
In lightweight construction, antagonistically operating belt and chain drives are used for the transmission of motion and power across larger distances. A disadvantage of using elastic traction means is that when the driving side (part of the rope which is pulled and is tight) is under tension, the slack side (part of the rope which is not pulled) sags. The consequence is that the sagging of the slack side during load changes produces considerable problems, especially with respect to the positioning accuracy and positioning speed. A further disadvantage of elastic traction means is that the force which can be transmitted is limited when tension springs are installed in transmission mechanisms.